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Date: Tue, 1 Nov 2022 02:43:46 -0500
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Subject: Re: [External] Re: WAL Replication query
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From: Ron <ronljohnsonjr@gmail.com>
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On 11/1/22 01:53, Laurenz Albe wrote:
> On Tue, 2022-11-01 at 06:44 +0000, Sacheen Birhade wrote:
>> If replication is in asynchronous then there will be data loss, right Laurenz?
> Why?  The data will perhaps show up on the standby a little later, but why is
> that data loss?  Remember that the question was about replication, and there
> was no mention of failover.

No, the question was about a crash during replication: OP (not Sacheen, 
unless that person is using two email addresses) explicitly asked "*When the 
primary crashes*  due an unforeseen reason (what happens)?"

If the two database systems are really busy, and especially if the network 
connection isn't fast enough, *async* replication means there *might* be 
some transactions committed on Primary which were queued for transmission, 
but hadn't yet made it to the Secondary, right?

-- 
Angular momentum makes the world go 'round.
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    On 11/1/22 01:53, Laurenz Albe wrote:<br>
    <blockquote type="cite"
      cite="mid:c1b6b89d6b89706acaeca9b4d45958f4739c4f28.camel@cybertec.at">
      <pre class="moz-quote-pre" wrap="">On Tue, 2022-11-01 at 06:44 +0000, Sacheen Birhade wrote:
</pre>
      <blockquote type="cite">
        <pre class="moz-quote-pre" wrap="">If replication is in asynchronous then there will be data loss, right Laurenz?
</pre>
      </blockquote>
      <pre class="moz-quote-pre" wrap="">
Why?  The data will perhaps show up on the standby a little later, but why is
that data loss?  Remember that the question was about replication, and there
was no mention of failover.</pre>
    </blockquote>
    <br>
    No, the question was about a crash during replication: OP (not
    Sacheen, unless that person is using two email addresses) explicitly
    asked "<b>When the primary crashes</b>  due an unforeseen reason
    (what happens)?"<br>
    <br>
    If the two database systems are really busy, and especially if the
    network connection isn't fast enough, <b>async</b> replication
    means there <b>might</b> be some transactions committed on Primary
    which were queued for transmission, but hadn't yet made it to the
    Secondary, right?<br>
    <br>
    <div class="moz-signature">-- <br>
      Angular momentum makes the world go 'round.</div>
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